In 2004, Dixon Chibanda was one of only two psychiatrists working in public healthcare in the whole of Zimbabwe. One day he hoped to open a private practice.

But when one of his patients, Erica, died by suicide, Chibanda’s plans changed. Two psychiatrists weren’t enough for a population of 12 million, he realised. He needed to find a way to provide mental health care for the most disadvantaged.

Chibanda decided to tap into an unexpected resource: grandmothers. As trusted members of the community, many were already working as community health workers across Zimbabwe. If they were also trained in psych therapy, Chibanda realised, these grandmothers could add treating depression to their list of responsibilities.

The project was called the Friendship Bench, because the grandmothers would often deliver therapy from benches outside local health clinics. As Alex Riley detailed in his award-winning Mosaic article last year, the project was massively successful in reducing depressive symptoms in disadvantaged populations.

Having started in Harare, Zimbabwe’s capital, it’s now spreading across the country – and beyond.

In New York, the bench has appeared in Harlem and the Bronx, and over 60,000 people have sat on it. It’s reached Malawi and Tanzania, and is currently being introduced in the Kenyan town of Kericho, where tea plantation workers have high rates of self-harm. Once it’s in place there, Chibanda wants to scale up to the rest of East Africa.

When we speak, he’s preparing to go to Rwanda to help introduce the bench. Fifteen thousand community health workers are waiting for training there. Later this year he’ll head to Liberia for similar work.

Chibanda is constantly using data to drive the next steps. Early on he saw that many users were living with HIV. Now a version of the bench is being integrated into an existing HIV programme. The hope is that improving patients’ mental wellbeing will also improve their adherence to treatment, lowering the level of HIV in their blood.

There’s also work being done to make the bench more accessible to young people. Some are put off by the idea of coming to a clinic and speaking to a grandmother, so university students are being trained to run a version specifically for 12- to 18-year-olds. Both this and the HIV programme are being evaluated in randomised controlled trials.

Back in Harare, the team is also studying the city’s 50 benches to work out how to optimise the programme in urban settings, while outside the capital, benches have spread to districts across Zimbabwe. The programme is shifting towards being village-based, but still links up with major health centres on difficult cases – grandmothers can refer patients upwards for medication or to clinical psychologists, for example.

But these higher-level services can’t always deliver the same quality of care as the Friendship Bench. It’s something Chibanda feels pressure over.

“The Friendship Bench has become so prominent, and the Ministry of Health has formally endorsed it as a national programme, so everyone is looking at us for the model that takes care of the next level,” Chibanda says. He’d love to help improve those higher-level services, but there’s too much work to do on the bench for now.

“There’s a lot of excitement, but excitement does not always result in funding,” Chibanda says. “It’s very difficult to get money.” He perseveres because he sees the effect the bench has.

Eventually, he’d like to see one in every city. “It sounds ambitious, but if you look at the model, it could be achieved. That’s what I’m really passionate about right now.”